1. Field of the Invention
The present invention relates to gaming machines and, in particular, gaming machines such as slot machines incorporating a bonusing game.
2. Statement of the Problem
It is well known in the gaming industry that bonus games attract and keep players at a gaming machine. The bonus game is typically another gaming machine or a random selection device which is enabled by a bonus qualifying signal from an underlying or primary gaming machine. A wide variety of bonus games, features, and devices are known some of which are set forth next.
The conventional WHEEL OF GOLD (trademark) and WHEEL OF FORTUNE (trademark) slot casino games incorporate a single play bonusing feature. A rotating wheel is activated by the player depressing a bonus spin button when certain indicia appears on the reels of the slot game and is used to award bonus payouts in a spin of the wheel. A separate multiplier may be used to multiply the bonus payouts. After the bonus spin, play resumes in the underlying gaming machine. These games are commercially available from Anchor Gaming and are disclosed in U.S. Pat. Nos. 5,823,874 and 5,848,932.
In EP 0 874 337 A1, "Gaming Machine with Bonus Mode" published Oct. 10, 1998 and owned by WMS Gaming, Inc., a bonus game involving multiple plays is presented for an underlying gaming machine such as a slot machine. Here a Bernoulli trial procedure is used to allow a player to repeatedly play a high odds bonus game (such as another slot game) and receive awards until a losing combination occurs (i.e., winning until losing). The hit rate in the bonus game is greater than 50% (preferably higher than 70%) which results in a much lower hit rate in the underlying game. This hit rate difference causes the player to endure the low hit rate of the underlying slot game in order to qualify for the high hit rate of the bonus game. The length of the bonus game is longer when the hit rate for the bonus game is higher. This bonus feature allows a player to win each bonus game and collect winnings until the player receives a losing combination (i.e., losing until winning). This is a variation of WMS Gaming's earlier bonus feature trademarked JACKPOT STAMPEDE which allowed the player in the bonus game to continually spin the bonus reels until receiving a winning combination. The recognized shortcoming with this earlier bonus feature was that the player's expectation of receiving meaningful bonus awards is crushed since the first winning combination to be hit is statistically a small award (i.e., a cherry). Other high odds and "win till you lose" bonus games are found in UK Patent Application GB 2 180 087 A published Mar. 18, 1987 and GB 2 084 371 A published Apr. 7, 1982.
U.K. Patent Application GB 2 222 712 A published Mar. 14, 1990 sets forth a slot machine main game interconnected with a slot machine secondary game. The player has the option of pushing button 18 which debits his credit meter by the appropriate amount to play the secondary game such as another slot game. Hence, the player gambles an amount in order to play the bonus game.
U.S. Pat. No. 5,393,057 pertains to an electronic gaming apparatus and method therefor wherein each play in the bonus is the result of successive underlying game play. The invention teaches the use of an electronic primary gaming device such as a poker or a slot machine and an electronic secondary gaming device based on bingo. When a winning combination such as three queens appears in the primary game, a space in the bingo matrix is turned over to reveal a bingo symbol. Play continues on the primary game until a winning sequence occurs in the bingo game. The right to play the bingo secondary game does not occur unless the player inserts three or more coins into the primary game. Play continues until the game achieves a bingo in which case the player receives a prize. UK Patent Application GB 2181 589 A published Apr. 27, 1987 pertains to a slot machine having a jackpot feature whereby the prize value is transferred between separate jackpot displays as successive games are played. Some of the reel symbols are overprinted with a number and when that number lands on the payline, it is used to climb a ladder. The ladder enables the player to obtain one or all of the prizes in the upper portion of the slot machine. For example, if the overlaid number lands the player on a first playing level, then the player receives all three prizes. If the overlaid number lands the player on a second level, then the player can select which one of the three prizes to receive. If the player lands on a third level, then it becomes a game of skill to select which of the three prizes he selects. Finally, if the player lands on a fourth level, then the prize is randomly selected. The prize may also be randomly doubled. U.S. Pat. No. 5,560,603 sets forth a plurality of slot machines interconnected to an electronic controller which displays a separate race game. Each time a particular predetermined combination of indicia appears in the display of a particular slot machine, a signal is generated from the slot machine which advances the racing element through a particular predetermined distance. If the player's horse reaches the finish line before a timer display times out, then the slot player wins an additional prize. The players in this patent are not racing against each other, but against a clock.
A former popular television game show trademarked THE JOKER'S WILD by Jack Barry Productions, Inc., permitted a player at the end of the show to play a giant slot machine until reaching a predetermined level of winnings, stopping with a lesser level of winnings, or being forced to stop (and losing everything) when a special symbol appeared on one of the three slot wheels. In the conventional THE JOKER'S WILD slot machine, the special symbol was a picture of a "devil."
A need exists to adapt the excitement created by such the aforesaid television game show through continued play of a bonus gaming machine such as a slot machine with the expectation of additional accumulation to an underlying gaming machine, but with the danger of losing all accumulated winnings. A need exists to provide a riskless initial award to the player upon entering the bonus game which cannot be lost in the bonus game. A need exists to provide a bonus feature for an underlying game that allows the operator to control the length, player enjoyment and player involvement in the bonus mode so that the bonus game doesn't have to be an automatic "win until a lose" or "lose until a win" occurs.